Hi Bob,

Welcome to Khan Academy! The "Get ready" courses for Precalculus and AP (college-level) Calculus may be helpful in brushing up on those areas before going on to the Precalculus and AP Calculus courses. The Get Ready for Precalculus course can be found here: https://www.khanacademy.org/math/get-ready-for-precalculus, and the Get Ready for AP Calculus course can be found here: https://www.khanacademy.org/math/get-ready-for-ap-calc. Taking the course challenges before going through the lessons in the course can help determine what you already know and what you may need to review more.

If you're looking to use Khan Academy for teaching, the Help Center has some great articles on how to use the Coach features here: https://support.khanacademy.org/hc/en-us/categories/200175820-For-Teachers. The Khan for Educators section can also help provide an introduction to the content on the site and how to use it in the classroom: https://www.khanacademy.org/khan-for-educators/k4e-us-demo.

I hope this helps! Please feel free to reach out if you have any further questions.